1. Field of the Invention
The invention relates to a suspension or rack frame for apparatus for the thermal treatment of substances, especially foodstuffs, having support rails with legs lying one above another for the edge regions of containers or the like.
2. Description of the Related Art
Suspension frames or rack frames of conventional type have support rails which are either fixed to two vertical profiles, the support rails being U-shaped in cross section, or appropriate horizontal legs are punched out from a sheet metal part and angled over so that they act in a way corresponding to the legs of U-shaped rails. This sheet metal part is turned over at the side edges in order to be able to be fixed to a side wall of the cooking appliance, just like the vertical profiles.
In these known embodiments, residues from the cooking operation in the form of organic materials are deposited on the support rails and, at the operating temperature of these apparatuses for the heat treatment of foodstuffs, referred to below as cooking appliances, tend to burn in and therefore adhere firmly to the surfaces. However, the surfaces in a cooking chamber must be satisfactorily clean in accordance with hygiene regulations. During the cleaning of the inner surfaces of cooking appliances, in particular in the interspaces between the containers carried by the support rails and the support rails of the suspension frames or rack frames, problems arise, since dirt and encrustations accumulate there and can be removed only by means of expensive manual labor. This problem is all the more important if account is taken of the fact that in large kitchen appliances, automatic washing devices for the cooking chamber are used. However, even such automatic washing devices cannot solve the problem, since the mechanical action of fast-flowing water jets and the chemical action of the cleaning agents used cannot remove the adhering residues in the aforementioned interspaces either, since the washing liquid does not get to all the points on these support rails, in particular not at those points which lie in what is known as the spray shadow of the water jets. The spraying apparatuses, which emit appropriate water jets, are often located in the upper region of the cooking appliances, so that the undersides of the support rails lie in the aforementioned spray shadow and are not reached by the water jets.